Soft Mold Process for 1-3 Piezocomposite and Its Application in High Frequency Medical Ultrasound Imaging

The high-frequency ultrasound transducer and imaging system are desirable for doctors and biologists to observe the many tissues with microstructures. Using the soft mold process, our lab is able to offer the 1-3 piezocomposites for high-frequency ultrasonic transducers above 40 MHz. For the fabrication of 1-3 piezocomposites in ultrasonic transducers, the mechanical cutting-filling method is limited due to the width of the dicing blade, and the etching technology also makes the microstructure shallow and uneconomic. Now, a novel soft mold process has been developed in our lab to fabricated the 1-3 piezocomposites with smaller pitch size ( $10\sim 70\ \mu \mathrm{m}$ ) and low-cost in mass production. Further, a miniature ultrasound transducer with the central frequency of 40 MHz and less than 0.5 mm in size have been designed and fabricated. The idea sensitivity and fine spatial resolutions can be obtained at the same time. Then, some animal tissues have been investigated by using the fabricated transducer. It indicates that the soft mold process is helpful to establish the industrial high-frequency ultrasound technology for medical imaging.